The http-proxy command parses a JSON file describing a list of reverse proxies.
This tool should only be used for testing: production code should manually
define proxy.Proxies with TLSConfig.
The example.json provides an example where http://eff.localhost:8080 is a
reverse proxy to the external resource https://www.eff.org and
http://wiki.localhost:8080 is a reverse proxy to https://www.wikipedia.org.